1971 Corvette Stingray - All Systems Go!

Our C3 Project Gets Ready To Hit The Road

We've Got Project Cars!Whether considering automobiles, homes, or antique furniture, purchasing someone else's used property generally comes with the aggravation of making repairs. As even a well-maintained house will eventually need a new roof, and a well-preserved piece of antique furniture will inevitably need to be refinished, a used automobile--especially a performance model--can likewise present a variety of issues that need to be addressed before the car is driven. Such is the case with our latest project, a '71 Stingray we recently picked up from eBay. Although we feel like we got a lot for our money with this purchase, there were several areas that needed attention before the car could be deemed roadworthy. This month we'll completely inspect our project vehicle, and perform some necessary routine (and not-so-routine) maintenance before hitting the road. Though we're working on a C3, remember that our techniques can be applied to any used vehicle prior to trusting it on the streets.

Knowing that even a fairly new Corvette may have been poorly maintained or improperly modified by its previous owner(s), we decided to give our Stingray a thorough mechanical evaluation to determine its roadworthiness. Of course, you may not care to perform this work yourself, but if you don't have the skills or desire to mechanically evaluate a used car you've recently purchased, we suggest taking it to a mechanic who can inspect it for you. As you'll see, we found a couple of safety-related items with our Stingray that could have led to catastrophic results had they gone unnoticed.

It's always a good idea to inspect a vehicle before purchasing it, but since we made our transaction over the Internet, we could only rely on the description and pictures the seller posted on the website. Luckily, the vehicle we purchased was basically as described in the advertisement, with the major mechanical components in pretty good shape. When inspecting a vehicle like ours, we generally begin with the obvious, like looking under the car for puddles of leaking fluids. Next, safety-related items such as the brakes, suspension, fuel and electrical systems, and seatbelts should be inspected. Of course, the airbags of newer cars should be checked as well, as they are sometimes not replaced properly after being deployed. Since our Stingray is a '71 model, we didn't have to worry about that.

What we did worry about was the odor of fuel when we started the car. Since there are basically two systems in a car that can catch fire, and the fuel system is one of them, we had to make sure ours was working properly and not leaking. Starting at the rear of the vehicle, we discovered that the fuel tank and main supply line had been replaced with new parts, but as we worked our way forward we found out where the scent of petrol was originating. The fuel line connecting the main supply line to the carburetor, through the filter, was a mismatch of steel tubing and rubber hose of various sizes. Making matters worse, several fuel-line clamps were incorrectly sized; this was the main cause of the leaks. After making the necessary fuel-system repairs, we moved on to the second system that could cause a fire, the car's electrical system.

MORE PHOTOS

There's a saying that when you buy a used vehicle, you're buying someone else's problems. This month we'll correct the problems we purchased, and make our Stingray project car roadworthy.

After unloading our new project vehicle, it was certainly temping to take it for a quick spin around the block. The distinct scent of fuel coming from the engine bay, however, encouraged us to look the car over closely before driving it. (Photo by Natalie Gleason)

Under the hood, we immediately found the source of the fuel odor. The fuel line had been pieced together with various sizes of steel tubing and rubber hose, and improperly sized clamps were allowing fuel to leak onto the intake manifold. This fire hazard is the first area we'll address.

After removing the questionable fuel lines and clamps, we used a tubing bender and flare kit to fabricate a single 3/8-inch aluminum fuel line to repair our leaks.

Noticing the fuel filter and line were a little close to the headers, we installed a clamp to secure the line to the car's frame.

A previous owner had installed a pair of electric fans, which were improperly wired directly to the alternator without fuse protection. We removed the fans (top) and wires, having decided to reinstall the original fan and shroud for proper cooling.

Luckily, the original shroud and fan were included with our car. We'll likely replace the radiator with a high-performance unit later, but for now the cooling system will be adequate for daily driving.

While under the hood, we noticed an area near the heater box that seemed to show evidence of a minor underhood fire. Though the damage was old and repairs had since been made, we traced the wiring and made an interesting discovery.

While all the gauges seemed to work in our Stingray, the oil-pressure gauge had been replaced with an aftermarket unit plumbed with cheap plastic line. Knowing this would be prone to future leaks, we decided to replace the line with something more substantive.

In what was likely an effort to get the environmental system's fan working, someone had wrapped the fuse for the heat and air conditioning in aluminum foil. Needless to say, we immediately replaced the fuse with one of the proper amperage.

Luckily, copper oil-pressure-line kits are available from most auto-parts stores. The copper line will be less likely to leak, and if pinched will seal itself rather than spewing hot oil onto the driver and passenger.

Since someone had already modified our instrument cluster to install an aftermarket mechanical oil-pressure gauge, we decided to take the opportunity to install a better-quality gauge while we had the panel out.

Putting our project car on the lift, we decided to change the fluids and lubricate the suspension bushings, while inspecting the undercarriage for any mechanical defects.

Servicing the engine (right) and transmission oil is fairly straightforward, so we performed those tasks and moved on to the suspension and brakes.

We inspected the calipers, rotors, and brake pads for signs of wear and found them all to be in great shape. We also checked the lines for signs of leaks, corrosion, or dry rot, but found none. Since the prior owner claimed to have recently rebuilt the brake system on this car, it was not surprising to find these parts in good shape.

We took advantage of the car being on the lift and tightened up the parking-brake cable for proper operation.

Working our way toward the rear, we found one of the strut-rod jam nuts loose on the passenger side. These should be checked fairly often, as driveline vibrations or wheel hop can loosen them. Fortunately, the other nut was tight and the strut rod hadn't moved, so we tightened the loose nut and moved on.

Servicing the rearend in our Corvette presented a dilemma. Since removing the differential cover meant disassembling much of the suspension, and because suction devices can't remove all the fluid, we decided to drill a drain hole and tap it for a pipe plug, making future differential-oil changes more practical.

After drilling the differential at its lowest point, just ahead of the cover, we used a magnet to remove any shavings that may have ended up inside the housing.

Using a 1/8-inch pipe tap, we threaded the 21/64-inch hole we had drilled in the housing. We again used the magnet to recover any metal shavings.

After performing the drain-plug modification, we flushed the differential with clean fluid to wash away any small shavings we didn't recover with the magnet.

After draining the differential fluid through our newly drilled hole, we serviced the unit with fresh gear oil and limited-slip oil additive.

Our project C3 has come a long way in a short time, but it still needs some work. Next month we'll improve the car's appearance, and then we'll be ready for some heavy modifications as we turn our Stingray into a real performer. We'd love to hear your ideas regarding modifications and potential project names, so send your suggestions to vette@sourceinterlink.com.

The threaded hole was then sealed with a 1/8-inch pipe plug. There are kits available for this modification, but we found everything we needed in our shop. As an alternative, all the necessary items to install a differential drain plug are also available at most hardware stores.

After finishing our inspection and maintenance, we dropped the lift and took our new project car for what turned out to be a problem-free maiden voyage. Having purchased this car for $5,600, and spent only a couple of hundred more to get it roadworthy, we're very pleased with its performance.

With our differential serviced, we checked all six universal joints. We found them to have been replaced with heavy-duty units by the previous owner.

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